The figure, not drawn to scale, is made up of 3 different triangles S, T and U. 15% of triangle S and 25% of triangle U is shaded. The shaded area of S is the same as the shaded area of U. What fraction of the figure is shaded if 20% of Triangle T is shaded?

Unshaded area of S	Shaded area of S	Unshaded area of U	Shaded area of U
17x1	3x1	3x3	1x3
17 u	3 u	9 u	3 u

15% = ¹⁵₁₀₀ = ³₂₀
25% = ²⁵₁₀₀ = ¹₄
20% = ²⁰₁₀₀ = ¹₅
The shaded area of S is the same as the shaded area of U.

Make the LCM of the shaded area of S and shaded area of U the same.
LCM of 3 and 1 = 3

¹₅ of T is shaded
= Shaded area of S + Shaded area of U
= 3 u + 3 u
= 6 u

Fraction of T that is unshaded 
= 1 - ¹₅
= ⁴₅ 

¹₅ of T = 6 u
⁴₅ of T = 4 x 6 u = 24 u

Fraction of the figure that is shaded if 20% of Triangle T is shaded
= ^{6 + 6}_{17 + 24 + 9 + 6 + 6}
= ¹²₆₂
= ⁶₃₁

Answer(s): ⁶₃₁